Understand Building Construction - Assignment Example

Construction Technology Name Tutor Date PART TWO ANSWERS 1. (a) Density (a) Density = mass /volume 7290kg/3.6m3 = 2025 kg/m3 (b) Volume = 3200 x 50 x 75mm = 12000000mm3 12000000mm3 / 1000000000 =0.12m3 Density = 7.8kg/0.12m = 65 kg/m3 Density for a and b= 2025 kg/m3, 65 kg/m3 2. Vol. of concrete lintel=1.800m x 0.150m x 0.100m= 0.027m3 Mass = Density*volume Mass of concrete lintel=2100*0.027=56.7kg 15mm/1000= 0.015m Volume of lintel bars=πr3h=3.14*0.015*0.015*0.015*0.1=0.00000105975 Mass of lintel=0.00000105975m3*7830=0.0082978425=0.008*2=0.016kg Mass of concrete=mass of cl- mass of lintel=56.7-0.016kg=56.64kg 3. The three rocks with the greatest percentage porosity are limestone, sandstone and shale. The percentage of porosity is related to the grain shape of the rocks in such a way that; the shape of the material controls the porosity in that round materials tend to fill the voids easily hence reducing the material’s porosity and tiny materials can fill the voids in between. 4. Examples of (a) metamorphic rocks: Marble - It mainly used in kitchen constructions due to its durability and elegance. (b) Igneous rocks: Granite -In construction, it is mainly used as a dimension stone and in making of flooring tiles. (c) Sedimentary rocks: Limestone -Apart from manufacture of cement, limestone is also used in landscape construction and is also quarried for use in roadbeds. 5. By definition Initial Rate of Absorption (IRA) is the quantity of grams of water absorbed in 1 minute over 30 inches squared of the area of brick bed. 6. Capillary action refers to the movement of a liquid along a solid surface caused by adhesion forces (the attraction between the liquid and solid molecules). It is affected by pore size in that it increases as the size of the pores decreases (Vink, 2003). 7. IRA affects the bond between the mortar and brick in that bricks with high power require mortars with high water retention ability since IRA is the ability brick to absorb water. 8. The need to have bricks kept dry as a way of enhancing durability. One adverse effect of excess water in bricks occurs when rain water hits the bricks and soaks the mortar causing the bricks and mortar joints to crack. Another effect occurs when water seeps up from the ground and leaves behind a tide line. The moisture formed above the left tide line eventually evaporates leaving behind salt crystals that later cause the mortar and bricks to break down (Stuart, 2000). 9. The content of carbon on mild steel affects the ductility or brittleness of mild steel in such a way that increasing the amount of carbon in steel affects both the hardness and strength. When the content is increased by about 1.5 to 2 percent, the ductility of mild steel increases. However, if the level of carbon is increased above this indicated amount, then ductility reduces making the steel very brittle. More carbon therefore strengthens the steel while at the same time; a lot of it makes the steel very hard and thus less ductile or more brittle (Oberg, et al, 1996). 10. a) Annealing: this the process by which metals are treated by exposing them to a given amount of heat for a predetermined amount of time and later cooled very slowly to room temperature in order to decrease the brittleness and improve the ductility of the metal. b) Normalizing: this the process of heating iron based metal to an indicated temperature that is above the range of transformation and then cooling it at room temperature an in still air. This is primarily done to soften the metal or to change the microstructure (gernross, 2000). c) Quenching: it is the process through which metals an alloy is exposed to heat at normalizing temperatures and then cooled rapidly to a critical temperature creating a martensitic structure. This is done to harden the metal. 11. Carbon steel is unsuitable for reinforcing concrete. One reason for this is the metal’s easy breakage ability unless it is handled with great care after heat treatment (Galbraith, 2009). The elasticity coefficient of this metal is also lower than that of mild steel hence achievement of a high elastic limit can hardly be fully utilized without excessively causing stress in the concrete causing the material to crack and the metal to corrode. 12. Corrosion is the process by which metals wear out as a result of occurring chemical reactions such as oxidation. It mainly occurs when a liquid or gas attacks exposed surfaces (metals). Warm temperatures, salts and acids accelerate this process (Jones, 1996). 13. a) Zinc in the construction industry, treated zinc is used for roofing and making gutters. Pure zinc is used to make other building materials when combined with other metals. Other building material other than sheet metal includes nails and gutters (b) Mild steel this is invaluable during roof construction. It serves as structural- steel during construction (c) Aluminium: this can be used in roofing, making gutters, wall panels, down spurts and flashing. It can be used as a decorative feature in elevator doors, window spandrels and entrances. (d) Lead: on ceramic glazes, lead is used as glazing or coloring element. It also forms glazing bars in stained glass. It can also be used as a sound proof layer in wall, floors and ceilings. (e) Copper: this can also be used in roofing as sheet copper. The metal can as well be shaped into angles and bends of roof edges and around chimneys and dormers. In the past, all screws, nails, cleats and bolts used on sheet copper had to be copper made. (f) Brass: this is mainly used as a decorative feature as a result of its gold like look. It is used to make bathroom accessories that include locks, door knobs, faucets and for piping. (g) Stainless steel. Stainless -steel rebars of high strengths can be used as reinforcements for concrete in the construction of bridges, buildings and highways. Other than making furnishings and furniture, it can be used in making stair rails, tubing due to its resistance to corrosion and making wall fixings and other decorative features such as door handles. 14. Corrosion on metals used in the construction industry can be avoided or reduced by painting, coating, anodizing and galvanizing. Anodizing is electrochemically coating of the metal surface to a durable, decorative, corrosion resistant, anodic oxide finish. Galvanizing is a technique that is corrosion preventive applied to cast iron, mild steel, and steel alloys. Here the pieces are in liquid zinc thus giving them a zinc coating. 15. Cement replacements are materials that are used as substitutes for some Portland cement in concrete. The main reason why the replacements are used is because they give various important enhancements or some modifications to the concrete properties. Such includes reducing the amount of cement that is required and thus cutting the costs. 17. The amount of water that is used in the concrete mixes usually affect the strength and density of the concrete. This is because it affects the water cement ration which in turn affects the durability of the concrete depending on the environment. Less water yields concrete which is impure and stronger while more water produces one which is slump. 18. In a high sulphate environment, water cement ratio of 0.4 or 0.8 can be used in an environment with high sulfate. This is because the concrete that is produced has a good resistance to the sulfate attack in long run. This is irrespective of the strength of the concrete. 19. some of the characteristics of concrete aggregate include: grading, durability, particle shape and texture of the surface, among others Grading is the determination of the particle size distribution for the particular aggregate. Its limit affects the amount of aggregate used and the requirements for cement and water. Shape of the particle and texture of the surface affect fresh aggregate in that those which are rough require more water than the smooth ones. This makes the cement used to be increased. This consequently affects the moisture condition. Abrasion affects the resistance of the aggregate when they are used constantly in the concrete. This is because they affect the wearing and polishing rates. 20. Well graded aggregate has a low porosity which is below 50%. This is because the aggregate adheres to the 0.45 power curve and is naturally crushed. The sand should pass the number 10 sieve and the mineral particles passes through the number 200 sieve. 21. Aggregate occupies about 70% to 80% by volume in the concrete. Aggregates are used with some binding medium like water, lime or bitumen for the formation of compound material like Portland cement or asphalt concrete. It is also used for base components and subbase cpurses in both flexible pavements and rigid pavements. 22. Materials which pass through the 75 micro meter sieve are referred as dense graded aggregates. Coarse aggregate is retained by the number 4 (4.75mm) sieve whilst fine aggregate passes through. 23. Hard woods Softwoods \ Softwoods have long cells known as longitudinal tracheid and occupy over 90% of their volume. In hardwoods, there are more cell types. Fibers in hardwoods are much shorter than in softwoods. The cell types in the hardwoods have a different arrangement from the softwoods. 24. Coefficient of thermal expansion is the change in the volume per a unit of volume of a certain substance that is produced by an increase in temperature by 1 degree Celsius. 25. Modulus of rupture is the measure of a force which is needed to break a certain substance across like a beam. Modulus of elasticity is the mathematical measure of a substance to deform once a force is applied to it. 26. Hardwoods are mainly used for furniture and in trimmings whilst softwood are used are mainly used in the construction of wood ware for home buildings and also for furniture 27. Polymers are mainly made up of carbon and hydrogen 28. Polypropylene can be used in manufacture of plastic pressure pumps in the construction systems. When nylon is used according to the required FDA standards it is used in applications for food contact. Nylon fabrics are also used by the army for shelter as they can keep warm temperatures. Polycarbonate is used for the manufacture of shields for riot, security windows, lenses and traffic lights. 29. Elastic deformation is the change of the shape a certain object when a load is applied. The object can recover from this state and get back to its state once the load is removed. Plastic deformation is the change in the shape of an object permanently once a force is applied. 30. The young’s modulus of elasticity is the point where there is actual rupture strength Part 5 - Failure modes Identify and discuss the different types of failure modes that can occur within structures. What is the function of failure mode and effect analysis? Mechanical failure – concrete is considered to fail when there is occurrence of significant cracks. This can be controlled by reinforcement. Carbonation – this is also called neutralization and is a chemical reaction which occurs between carbon dioxide in the air and calcium hydroxide and hydrated calcium silicate found in the concrete. Alkali silica reaction It is the reaction of amorphous silica found in aggregates with the alkalis from cement-pore solution. The silicate which is formed causes swelling which can cause cracking (Roberta, 2001). Failure mode and effect analysis is a method for analyzing the reliability of a system so that necessary actions can be made to prevent the problem from happening. This enhances the reliability through design. It identifies the failure modes and hence determines its effect to product operation. It helps to mitigate these failures (Magdalena, 2001). Part 6 - Glossary of terms Accreditation: - this is a term that is mainly used in the British Columbia for the bargaining of multi employer construction Bonding: - a performance bond is provided by the construction companies as one of the conditions for award of a project. The company which bonds agrees to provide funds to finish the job if the bonding company is unable. Bidding requirements: - this is a description that is written for the procedures that are used for submitting of bids (Akiyama, 2003) BIM- it is an acronym for Building Information Model- it is a 3D model representing a building made from special software. Bridging: - a method for project delivery where the owner hires a professional to do the preliminary and conceptual design. A design builder then contracts to finish the design and the construction Construction documents: - it describes the building and how to build it. Construction manager: - there is a construction manager who performs the action of scheduling the operations of the multiple-prime-contractors and one who is responsible for the provision of pre construction services to an owner of a project which the contractor will be the prime one. Constructor: - this is any particular entity that performs a construction Contract documents: - these are documents that describe the details of the contractor obligations Contractor: - this is an entity that has a relationship based on the contract with some other entity Design build: - a project delivery method where the owner hires one entity to design and construct the project. Design builder: - one entity where the owner constructs for both design and construction Design criteria: - requirements of an owner and the regulatory agencies which have the jurisdiction Designer: - a professional who is conversant with the particular kind of work to be performed. Facility: - a term preferred for a construction project result. Performance requirements: - according to Bohlman (2006)these are statements that regard the performance of a certain facility, the elements built for a certain facility, and the products that make up the facility. Performance specifications: - this is specifications that are written in order to achieve some characteristics and apply to the entire facility, parts of it and the products that are used. Perspective: - a design system for documentation which is automated which is designed for the design build. Perspective specifications: - these are specifications which are written so as to require that certain products have specific characteristics. Proposal documents: - this is a proposal written by the design builder to describe what the person wants to build. Claim of jurisdiction: - a building trade union has a constitution which sets the union’s view of its constitutional jurisdiction; this may often overlap with some other jurisdiction from other unions. The said claim is often wider than this scope. Consolidation order: - this is a board order which is usually given before registration bargaining. It describes the trades that may take the strike votes or the lockout votes. Cost plus contract: - it is a contract in which payment to the contractor is on a percentage of a fee that is fixed over labour and material cost. Double breasting: - it is the running of two companies which are affiliated; one is a union company and one a non union company (Bolen, 2008). Enabling clauses: - in a collective agreement, an enabling clause allows the contractor to request the union to allow them to bid the job at wages less than the union wages so as to meet non union competition. EPC contract: - it is a type of contract where a contractor provides engineering, procurement, and the construction work on a certain project. Green-book: -it is a publication that sets out all decisions of record and the umpire awards involving disputes which are jurisdictional between trade unions for buildings. Hiring hall: - hiring halls are run by trade unions for supply of contractors with trade persons who are qualified. Registration of union members is done in a hall. Jurisdictional disputes: - this is dispute which ensues between two trade unions on where to perform a certain kind of job in. Leapfrogging: - this is when contractors with some ongoing work settle with one contractor and then strike with another contractor for higher rates. Local hire: - one of the conditions used whilst getting a project, the owner has to set up some local residents for a certain project (Kinanne, 2002) Markup meeting: - this is a meeting organized by the contractor where the subcontractors and the union representatives meet to discuss the work that will be assigned to some particular trades. Merit shop contractors: - it is an association that is involved with the promotion of constructions that operate under a different set of rules than those in the union. Name hire: Some of the construction agreements do allow the employer to ask a union to dispatch some particular individuals to their jobs instead of the people topping the hiring-hall list. Registration: - Registration is a statutory system which allows an organization belonging to an employer to become the bargaining agent for all the unionized employers who are within a certain part of a construction industry. Risk management: - Risk management is a term for an insurance industry used for the description of the ways in which to protect some of the assets of the enterprise from the major losses that can be incurred. Sector: - this is a division of any construction industry that is specified in regulations as they are determined by the characteristics of the work. Spin off: - this is a company that is created so as to work free of union obligations imposed on related companies. Territorial jurisdiction: - Building trade-unions create the locals through some charters. These charters do authorize the locals to operate within specified territories. Some construction trade unions have province wide jurisdictions. Others usually have limited territories within the provinces. Trade jurisdiction: - this is a trade as is defined by the Board so as to define “parts of the construction-industry” for the registration. Such jurisdictions are similar to jurisdictions as are set between the building-trades, though they are not identical (Wiseman, 2007). They usually depend on the Board discretion, but not the building-trade rules. Union label clauses: - it says that all or some materials which are brought onto a certain construction site must always have been made in union shops. These clauses are predominantly important for boilermakers and pipe-fitters trades. References Akiyama, M. et al (2003). Polymer Degradation and Stability 80, 183-194. Alan Weisman, (2007). The World Without Us, NY: St. Martin's Press. Alonso-Magdalena et al. (2006). "The Estrogenic Effect of Bisphenol A Disrupts Pancreatic β- Cell Function In Vivo and Induces Insulin Resistance". Environmental Health Perspectives 114 (1): 106–112. Bohlmann, G. (2001) Biodegradable polymer life cycle assessment, Process Economics Program. Galbraith, Kate ( 2009). The New York Times. Retrieved April 26, 2010 from http://greeninc.blogs.nytimes.com/2009/06/11/ftc-sends-stern-warning-on- biodegradable- marketing-claims/. Gayle, Margot &Waite, John (1980). Metals in America's Historic Buildings: Uses and Preservation Treatments, Washington: U.S. Dept. of the Interior, Heritage Conservation and Recreation Service, Technical Preservation Services Division. Gerngross, T. & Stuart, S. (2000)Scientific American. 283, 37-41. Guruswamy, Sivaraman (2000). Engineering properties and applications of lead alloys. New York, NY: Marcel Dekker Kinnane, Adrian (2002). DuPont: From the banks of the Brandywine to miracles of science. Baltimore, Md.: Johns Hopkins University Press. pp. 116–125. Nelson, T. & W. Bolen (2008). "Construction Aggregates". Mining Engineering 60: 25–26. Oberg, E.; et al. (1996). Machinery's Handbook (25th ed.). Industrial Press Inc. Roberta Robinson ( 2001). Who’s Minding the San Rafael Rock Quarry?. Marin County Civil Grand Jury. Retrieved 2008-01-03 from http://www.co.marin.ca.us/depts/GJ/main/cvgrjr/2000gj/ssrq/SRRQREPT.pdf. Smith, William F. & Hashemi, Javad (2006), Foundations of Materials Science and Engineering (4th ed.), McGraw-Hill. Vink, E. et al. (2003) Polymer Degradation and Stability. 80, 403-419. Read More